Stop joint for multiconductor fluid filled cables



Aug. 4, 1942. sc 2,292,114

STOP JOINT FOR MULTICONDUCTOR FLUID FILLED. CABLES Filed Aug. 16, 1940 PRESSURE PROOF FLUID FILLED COVERINGOF SILK PAPER- TUBE- /TUBE ,4 HEAD WALL l6 /5 9a VALVE FLUID FILLED Ihventor: AlFred Frlcsche, by 7 His Attofrfiey.

Patented Aug. 4, 1942 UNITED STATES PATENT OFFICE STOP JOINT FOR MULTICONDUCTOR FLUID FILLED CABLES Application August 16, 1940, Serial No. 352,960 In Germany September 29, 1939 1 Claim.

Stop joints for multi-conductor, fluid filled cables have to fulfill various requirements with means as simple as possible and confined to the smallest possible space. Among other conditions, it is required that the individual conductors entering the end parts of the stop joint be introduced into the interior of the center part thereof in a fully sealed-up and pressure resisting fashion, so that the passage of fluid from one cable length to its connected length is prevented. Furthermore, the stop joints have to be so constructed that a liquid impregnating agent can, Whenever desired, be freely admitted to the joint casing.

The object of my invention is the provision of an improved stop-joint for fluid filled cables which is simple in construction and reliable in operation.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying specification and the claim appended thereto.

In the accompanying drawing which is illustrative of my invention is shown a stop-joint partly in longitudinal section and partly in elevation.

It the figure, I represents the ends of the sheathed cable lengths to be joined, 2 the conically shaped housings forming the end parts of the stop joint, 3 the spread-out conductors of the cable, 4 the chambered casing or middle part of the joint, and 5 the connection piece or sleeve which is thoroughly and strongly welded or otherwise united to each pair of conductor ends, the outer diameter of said sleeve being approximately equal to that of the short tube or pipe 6 supported by the head of a housing. Each conductor is enclosed in such a tube, one end of which is seated on and sealed to the partition or head wall ll] of the housing. A wound covering of insulation, such as paper or its equivalent, for each conductor adjacent the sleeve 5 is shown at 1. The tube 6 and the covering 1 have wound thereon a dense and pressure-proof covering 8 of suitable material such as for instance insulating silk alone, or in combination with an oil-proof band of synthetic material.

For admitting oil or other insulating fluid under positive pressure whenever desired, a conduit 9 provided with an angular valve 9a is arranged centrally inside of the housing and is welded at H to the center of the'partition or head wall Ill. The spaces between the conductors and the wall of the sheath act as channels for the fluid filling of the cables. These channels may be supplied with fluid under positive pressure in any Well known or suitable way.

It will be noted that the chambered end parts or housings 2 of the joints are conical to afford space to permit separating or spreading of the conductors preparatory to the jointing operation. The outer end of each housing is secured to the sheath of the cable in a fluid tight manner as by a wiped soldered joint l3, for example. The inner end of the housing is closed by the partition or head wall 10, which in addition to serving as a means for separating the fluid contents of the chambers also serves as a closing means for an end of the central part or casing 4 of the joint. To this end, the wall or head II] is of larger diameter than the end of the housing and has a curved wall or flange I4, a portion of which extends parallel to the cylindrical casing 4. To a limited extent the inner ends of the housing and easing are in telescopic relation, thereby reducing the overall length of the stop joint. The ends of the flange and casing are welded or otherwise united to form a fluid tight joint. Such a union is indicated at l6. When for any reason it becomes desirable to remove the casing 4, the welds can be cut away and the casing slipped endwise. Because of the arrangement, ample material is provided at the ends of the parts for re-welding. The arrangement of the flange [4 forms an adequate support for the casing 4 and thereby permits the use of simple tubing for the casing as distinguished from building it up of separate parts. The arrangement of the head wall or cover ll] of the housing affords a suitable support for the short tubes 6 which enclose the conductor covering. By locating the valved conduit 9 in the position shown, it decreases the possibility of it being injured because of the protection afiorded by the relatively large diameter of the central casing. Located as it is, access to the valve controlled conduit is easily had even though the central part of the casing is in contact wtih a supporting structure.

The sealing of the conductors where they pass from the confines of the chambered housing into that of the central or joint casing is achieved by a combination of the short pieces of tube 6 which are welded or otherwise secured to the head wall IU of the housing and a tight wrapping of pressure resisting material 8. Admission of fluid to the joint casing is effected through the conduit 9 subject to the control of the valve therein. Since one end of the conduit extends through a side wall of the housing, the valve therein may be manipulated without disturbing the housing. The fluid may be introduced into the housing under positive pressure by any suitable arrangement including the necessary piping, as for example through an opening in the side wall and its closing means I5.

What I claim as new and desire to secure by Letters Patent of the United States is:

A joint for fluid filled cables comprising, in combination, a plurality of conductors, liquid impregnated insulation thereon, metal sheaths for the conductors, a tubular casing surrounding the connected ends of the conductors. detachable housings having diverging walls located one at each end of the casing through which the conductors extend, each housing being soldered at its outer end to a sheath, a head for the inner end of each housing of larger diameter than the end forming an integral part thereof and having a peripheral axially extending flange telescoping within the inside of the casing, the ends of the casing and the ends of the flanges being united by a sealed joint, short lengths of metal tubing within the casing secured to the opposing heads and through which the conductors extend, pressure proof tubular coverings of insulation, each surrounding a conductor and also the lengths of tubing carried by the heads to separate the conductor from the contents of the casing, and a conduit extending through one of the heads and a wall of the adjacent housing through which the casing is filled with fluid.

ALFRED FRITSCHE. 

